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An Introduction to Helium Reflex Loudspeakers

This paper describes how the use of a gas with a negative Joule-Thompson coefficient will provide a means for effectively increasing the volume of a loudspeaker enclosure. The Joule-Thompson effect describes how real gases deviate from ideal behavior. A negative coefficient indicates the gas heats upon expansion and cools on compression, as well as to what degree. Using this principle, we have developed an enclosure theory that allows either a large reduction in enclosure volume without affecting performance, or a significant improvement in performance at a given volume. This new principle is designated Helium Reflex.